// in.c
// Sample C program with for loop array manipulation.

int main()
{
    int a[101], b[101];
    int i;

    b[1] = 4;
    a[100] = 7;
    
    for (i=2; i <= 99; ++i) {
        a[i] = b[i-1] + a[i-1] + 1;
        b[i] = a[i+1] + 5;
    }
        
    printf("%f\n", a[9]);
    return 0;
}


